1. Field of the Invention
The present invention generally relates to a lamp and, more particularly, to a lamp that allows air driven by a cooling fan to reach a circuit board for cooling purpose.
2. Description of the Related Art
FIG. 1 shows a conventional lamp 7 disclosed in Taiwan Patent No. M330426 entitled “COOLING STRUCTURE OF A LAMP”. The lamp 7 includes a cooling seat 71, a circuit board 72, a light-emitting diode (LED) module 73, a cooling fan 74 and a head 75. The cooling seat 71 has a recessed portion 711 and a receiving portion 712 opposite to the recessed portion 711. The circuit board 72 and the LED module 73 are mounted in the recessed portion 711. The cooling fan 74 is mounted in the receiving portion 712. The head 75 is electrically connected to an external power and the circuit board 72, as well as to a periphery of the receiving portion 712. The cooling seat 71 includes a plurality of cooling vents 76 that allows the external air to flow into the receiving portion 712 therethrough. The head 75 includes a plurality of air-guiding holes 77 that allows the external air to flow into the receiving portion 712 therethrough. In this arrangement, the cooling fan 74 draws air into the receiving portion 712 via the air-guiding holes 77 and expels air from the receiving portion 712 via the cooling vents 76 during the operation thereof. In this mechanism, the heat generated by the head 75 is expelled.
When the lamp 7 operates, the heat of the head 75 can be discharged but the heat generated by a plurality of electronic components of the circuit board 72 cannot. Since the electronic components tend to overheat during the operation of the lamp 7, breakdown of the lamp 7 is easily caused. The service life of the lamp 7 is even shortened.
It is often required to install the lamp 7 in a decorated ceiling for aesthetics. However, this will affect the ventilation and cooling effects of the lamp 7. This is because the cooling vents 76 and the air-guiding holes 77 that are respectively formed on the cooling seat 71 and the head 75 will be settled in a non-ventilated space above the decorated ceiling while exposing the LED module 73 to the room for illumination purposes. The non-ventilated space between the decorated ceiling and the concrete ceiling in the floor of a building usually lacks ventilation. Therefore, heat may accumulate in the lamp 7, shortening the service life of the lamp 7. In addition, since the cooling vents 76 and the air-guiding holes 77 are respectively formed on the cooling seat 71 and the head 75, aesthetics integrity of the lamp 7 is poor.
FIG. 2 shows a conventional lamp 8 disclosed in Taiwan Patent No. M408005 entitled “SLEEVE LAMP SEAT WITH COOLING FUNCTION”. The lamp 8 includes a sleeve lampshade 81 and a fan 82. The sleeve lampshade 81 forms a plurality of holes 811 on the bottom thereof. The fan 82 is mounted in the sleeve lampshade 81 for guiding the air into and out of the lamp 8 via the holes 811 to prevent the lamp 8 from overheating.
The lamp 8 further includes a circuit board 83 mounted in the sleeve lampshade 81. The circuit board 83 is mounted with a plurality of electronic components 831 for controlling the operations of the lamp 8. Since the electronic components 831 are located in a narrow space between the sleeve lampshade 81 and the circuit board 83, the air driven by the fan 82 cannot reach the electronic components 831 for cooling purposes. Consequently, the electronic components 831 will overheat during the operation of the lamp 8, leading to breakdown of the lamp 8 and shortening the service life of the lamp 8.
FIG. 3 shows a conventional lamp 9 disclosed in Taiwan Patent Publication No. 201030280 entitled “LAMP”. The lamp 9 includes a housing 91, a light-emitting element 92, a circuit board 93 and a cooling fan 94. The housing 91 forms a plurality of air inlets 911 and a plurality of air outlets 912. The light-emitting element 92 is mounted in the housing 91 and electrically connected to the circuit board 93. The circuit board 93 is mounted with a plurality of electronic components 931. The cooling fan 94 is mounted in the housing 91 and directly drives the air through the electronic components 931 of the circuit board 93 to expel the heat of the circuit board 93, ensuring the normal operation of the lamp 9.
In the lamp 9, although the air driven by the cooling fan 94 is allowed to reach the circuit board 93 for expelling the heat of the electronic components 931, the lamp 9 has poor appearance integrity and complex structure due to the arrangement of the air inlets 911 and the air outlets 912. Furthermore, when the lamp 9 is installed in the decorated ceiling while the light-emitting element 92 is exposed to the room for illumination purposes, the ventilation and cooling effects of the lamp 9 are affected because the air inlets 911 and the air outlets 912 are located in the non-ventilated space above decorated ceiling. As a result, the service life of the lamp 9 is shortened. In light of this, it is necessary to improve the conventional lamps.